I have an aquarium screen saver with bubbling noises and a software which will ring out Big Ben bongs at a set time. When I was recording a tape, the screen saver launched and the bubbling noise was dubbed into my file. When Big Ben chimed, those also were included in my songs. So now I turn OFF all screensavers, power savers, and other software with sounds of any sort while I record!

schiller wrote:Whether or not such unwanted sounds get captured along with the wanted sig may have to do with your sound card settings.

For the recording input there is (at least on some sound cards) a "channel" named "What I hear" and it seems you are recording that one instead of directly the output of the playback channel.

But this remains speculation until I ever find a decent block diagram of the typical sound card play/record arrangement which I confessedly have not understood fully until this day.

Harald

Yes, there is a certain lack of clarity in the documention produced by most soundcard manufacturers and it isn't helped when they are use different terms for the same thing, eg on my system 'what I hear' is called 'stereo mix'.

For block diagrams, you might like go to www.datasheetarchive.com and search for 'ac97 codec'. This will lead to the datasheets for the chips used on soundcards, most of which show an overall block diagram.

I might like to add one additional tip to remember while recording.
The stylus is sensitive enough that it'll pick up ambient room noise if that noise is loud enough. Case in point: during recording of Zoltan Kodaly's Symphony in "C", our dog and cat got into a mêlée. When listening to the resultant CD, I could hear faint but distinct barking during a portion of the Symphony's second movement.